The present invention relates to the treating of liquid metal in a refining or holding vessel by injection of gas through the pouring outlet in the bottom wall of the vessel, which outlet is controlled by a slidable gate closure mechanism. This invention is particularly applicable to the refining of steel in a ladle or other holding vessel.
It is known that various metal refining treatments may be carried out in a vessel by the underbath injection of a gas through the side wall or bottom wall of the vessel. Such treatments include desulfurizing, dephosphorizing, deoxidation, and making alloy additions. Heretofore, however, any required piping remained with the vessel and was not detachable therefrom upon completion of the metallurgical treatment.
A common method of injecting a treating gas into a liquid metal bath is through a porous plug in the bottom wall of the vessel. Gas will pass through the interstices of the porous plug into the bath, but molten metal will not pass through the plug. Very high pressures are required to force sufficient quantities of gas through the plug to accomplish the desired treatment. The present invention avoids the problems inherent in the use of porous plugs.